The field of medicine is experiencing a genomics revolution. The need for physician scientists and investigators experienced in genomic and genetic methodologies and able to translate basic science discoveries in genomics into clinical care has never been greater. The major goal of this postdoctoral research training program is to train the future leaders of medical genetics and genomics who will emerge from a variety of training pathways with varying amounts of research experience. Many will have M.D. degrees, others will be M.D.-Ph.D.'s with clinical training in Medical Genetics, Pediatrics, Medicine, Psychiatry, Pathology, and other specialty areas will be eligible for support from this training grant. Funding for 5 training slots per year is sought. The clinical training years (typically year 1 for Categorical Medical Genetics trainees and years 1-3 for combined Pediatric and Medical Genetics trainees) is funded by the Perleman School of Medicine at the University of Pennsylvania (UPenn) and The Children's Hospital of Philadelphia (CHOP), while funds for the research years of the overall training program are sought from this training grant. During the Medical Genetics Research Fellowship years supported by this Training Grant, the fellow devotes essentially 100% effort to research in a basic science laboratory. Research opportunities are extremely diverse with training in the laboratories of 43 Faculty from 6 core departments at CHOP/UPenn. Fields of research may encompass those areas that impact human genetics including, but not limited to: genomics, molecular genetics, cytogenomics, biochemical genetics, mitochondrial genetics, developmental biology, cellular biology, bioinformatics, systems biology, pharmacogenetics and others. During the research years, the trainee also takes seminar courses, attends journal clubs, research meetings, and departmental research retreats, and carries out minimal clinical activities, not to exceed 15% effort. Training stipends for the 2-3 years of research are requested in this application. The M.D. trainee will likely require further research training (not covered by this training grant), which might be acquired through an additional postdoctoral research experience or a protected faculty appointment with considerable mentoring from a senior faculty member. !